The present invention relates to a method for determining the closing point of a pump piston relative to a transverse bore in the corresponding pump cylinder. In a known method the pressure rise caused by closing the transverse bore with the pump piston is utilized to determine the end point. Such a method is known from my U.S. patent application Ser. No. 542,070 now U.S. Pat. No. 4,546,648. To accomplish this method a test fluid must be used, thereby resulting in relatively large equipment expenses. Another disadvantage of the known method is that it is only usable for the named purpose.